Conventionally, a mounting method is performed, in which chip components (IC, resistor, capacitor and the like) are press-bonded on a liquid crystal module, a glass base board, or a plastic base board at a time by using an adhesion material such as an anisotropic electro-conductive film and the like.
The anisotropic electro-conductive film (also called ACF) is a high-molecular film in which electro-conductive particles (solder, or a material in which plating is applied to resin balls) are dispersed; and is a connection material that has three functions of adhesion, electrical conductivity and insulation. By press-bonding with the anisotropic electro-conductive film interposed between upper and lower base boards or between a base board and a chip component, it is possible to: electrically connect upper and lower electrodes to each other via the electro-conductive particles; give electrical conductivity in a vertical thickness direction; and give insulation in a surface direction. Because of this, the anisotropic electro-conductive film is preferably used for bonding base boards to each other and mounting a chip component on a base board.
Besides, a method is also performed, in which the anisotropic electro-conductive film is attached to electrode portions such as a connection bump and the like that are disposed on a base board; a plurality of chip components are mounted on the anisotropic electro-conductive film; a press-bonding head is placed on the chip components; pressing is performed while heating in whole to perform the press-bonding at a time. Here, considering unevenness in height dimensions of the components (e.g., chip components) to be press-bonded, a press-bonding method is already proposed, in which an elastic sheet is interposed between the press-bonding head and the component to be press-bonded; and the heating and pressing are performed by means of the press-bonding head, whereby defective press-bonding is prevented (e.g., see a patent document 1).
Besides, a liquid crystal display device is so structured as to include: a liquid crystal panel portion in which liquid crystal is injected between two glass base boards; and a wiring region where chip components like a drive IC chip and the like and various electronic components are mounted on a glass base board around the liquid crystal panel portion. Because of this, conventionally, a mounting method is employed, in which a plurality of chip components are press-bonded at a time by using an adhesion material such as the anisotropic electro-conductive film and the like. Besides, on the base board that serves as the wiring region, a flexible printed wiring board (FPC), which is connected to a wiring and an external signal output means, is disposed.
To achieve size reduction and sophisticated function of a liquid crystal display device on which many chip components are mounted, it is important to mount, in a limited space, a plurality of chip components at accurate positions and in correct attitudes. Besides, connection reliability is also required which allows correct electrical connection between chip components and connection portions like an electrode, a connection bump and the like formed on a base board.
Even if the performance of a chip component to be mounted is good, if the component is not accurately mounted on a base board, a product (liquid crystal display device) which fulfills a predetermined performance is not obtained and stabilization of the product quality is not achieved, which leads to a defective product.